1. Field of the Invention
The present invention relates to a combination altering apparatus for altering combinations of corresponding relationships between operation lever operation directions and actuator drive directions. The present invention also relates to an operation lever apparatus. More specifically, the present invention relates to an operation lever apparatus that can hold an operation lever in an operation position or release that condition of holding.
2. Description of the Related Art
In hydraulic shovels in general, four working members, namely an upper revolving superstructure, a boom, an arm, and a bucket, are actuated by operating left and right operation levers deployed to the left and right of the operator""s seat.
Until now, the combinations of corresponding relationships between the operation directions of the two (left and right) operation levers, on the one hand, and the actuation directions of the four working members noted above, on the other (hereinafter called operation patterns) have differed from one hydraulic shovel manufacturing company to another.
Accordingly, when an operator accustomed to the control operations of a hydraulic shovel made by company A operates hydraulics shovels manufactured by company B and company C, fatigue is increased because the operator is not accustomed to the control operations thereof. An enormous burden is also placed on the operator because he or she must perform control operations while bearing in mind the differences in operation patterns.
That being the case, inventions and models relating to;operation pattern switching for switching operation patterns in hydraulic shovels have been devised previously.
In Japanese Utility Model Application Publication No. 38935/1994 is described a model for switching hydraulic shovel operation patterns by switching hydraulic fluid paths.
In contrast therewith, the working members in a skid steer loader are comprised of a boom and a bucket. Left and right running bodies (wheels or crawlers) are actuated by two (i.e. left and right) running actuators deployed on the left and right of the vehicle body. The left and right running bodies are driven independently by hydraulic motors deployed on the left and right, respectively, of the vehicle body. The running body on the left side of the vehicle body is independently driven and the speed thereof independently changed by a drive mechanism provided exclusively for the left side. Similarly, the running, body on the right side of the vehicle body is independently driven and the speed thereof, independently changed by a drive mechanism provided exclusively for the right side. Each of these drive mechanisms is configured by a hydraulic pump and a hydraulic motor.
In a skid steer loader, four running bodies or working members consisting of a boom, a bucket, and two (left and right) running bodies are actuated by the operation of left and right operation levers deployed on the left and right of the operator""s seat.
The combinations of corresponding relationships between the directions of operation of the left and right operation levers and the actuation directions of the four running bodies and working members (i.e. the operation patterns) differ according to the manufacturer of the, skid steer loader. Operation patterns are diagrammed in FIGS. 12(a), 12(b), and 12(c).
As diagrammed in FIG. 12, a left operation lever 6L and a right operation lever 6R are deployed to the left and right of an operator""s seat 80.
In the operation pattern diagrammed in FIG. 12(a), the operation directions of the left operation lever 6L, the operation directions of the actuation directions of the running body on the left side (left running forward, left running back), and the actuation directions of the boom (boom up, boom down) correspond, while the operation directions of the right operation lever, the actuation directions of the running body on the right side (right running forward, right running back), and the actuation directions of the bucket (bucket dump, bucket excavation) correspond. In other words, the left and right running bodies are actuated by operations of the left and right operation levers 6L and 6R.
In the operation patterns diagrammed in FIGS. 12(b) and 12(c), the operation directions of the left operation lever 6L and the actuation directions of the left and right running bodies (forward, backward, turn right, turn left) correspond, while the operation directions of the right operation lever and the actuation directions of the boom and the bucket (boom up, boom down, bucket dump, bucket excavation) correspond. In other words, the left and right running bodies are actuated merely by the operations of the left operation lever 6L.
In the operation pattern diagrammed in FIG. 12(b), moreover, the left and right running bodies are driven to turn by a rotating operation of the left operation lever 6L, and the bucket is actuated by a rotating operation of the right operation lever 6R.
FIG. 13 is a hydraulic circuit diagram for the case where the left and right running bodies are actuated merely by operating the left operation lever 6L (cf. FIGS. 12(b), 12(c)).
As diagrammed in FIG. 13, a left operation lever device 5L comprises a left operation lever 6L, a bridge circuit 45 wherein four shuttle valves 41, 42, 43, and 44 are connected in a ring, and hydraulic lines 11, 12, 13, and 14 that connect the left operation lever 6L to the bridge circuit 45. The lines 11, 12, 13, and 14 are lines wherein hydraulic signals (pilot pressures) are generated according to operations of the left operation lever in the forward, backward, right, and left directions, respectively.
The lines 11, 12, 13, and 14 are connected to the inflow port for the shuttle valves 41 and 42, the inflow port for the shuttle valves 43 and 44, the inflow port for the shuttle valves 42 and 43, and the inflow port for the shuttle valves 44 and 41, respectively.
The outflow ports of the shuttle valves 41, 42, 43, and 44 are connected to the forward position port 32F of a control valve 32 for the right running body, the forward position port 31F of a control valve 31 for the left running body, the backward position port 32R of the control valve 32 for the right running body, and the backward position port 31R of the control valve 31 for the left running body, respectively. The volume of a hydraulic pump 33 for the left running body is changed by the left running body control valve 31, and the volume of a hydraulic pump 34 for the right running body is changed by the right running body control valve 32.
The left running body hydraulic pump 33 actuates the left running body through a hydraulic motor. When a hydraulic signal (pilot pressure) acts on the forward position port 31F of the left running body control valve 31, the volume of the left running body hydraulic pump 33 is changed on the forward side, and the left running body is actuated in the forward direction. And when a hydraulic signal acts on the backward position port 31R of the left running body control valve 31, the volume of the left running body hydraulic pump 33 is changed on the backward side, and the left running body is actuated in the backward direction. Similarly, when a hydraulic signal acts on the forward position port 32F of the right running body control valve 32, the volume of the right running body hydraulic pump 34 is changed on the forward side, and the right running body is actuated in the forward direction. And when a hydraulic signal acts on the backward position port 32R of the right running body control valve 32, the volume of the right running body hydraulic pump 34 is changed on the backward side, and the right running body is actuated in the backward direction.
Accordingly, when the left operation lever 6L is operated in the forward direction, the vehicle is made to xe2x80x9crunning forward,xe2x80x9d and when it is operated in the backward direction, the vehicle is made to xe2x80x9crunning in backward.xe2x80x9d When that operation lever 6L is operated in the right direction, the vehicle is made to xe2x80x9cturn to the right,xe2x80x9d and when it is operated in the left direction, the vehicle is made to xe2x80x9cturn to the left.xe2x80x9d
A right operation lever device 5R comprises a right operation lever 6R and hydraulic lines 15, 16, 17, and 18 that connect to the right operation lever 6R. The lines 15, 16, 17, and 18 are lines wherein hydraulic signals are generated in response to operations of the right operation lever 6R in the forward, backward, right, and left directions, respectively.
The lines 15, 16, 17, and 18 are connected, respectively, to the boom down position port 72a of a boom control valve 72, the boom up position port 72b of the boom control valve 72, the bucket dump position port 73a of a bucket control valve 73, and the bucket excavation position port 73b of the bucket control valve 73. To the boom control valve 72 and bucket control valve 73 is supplied hydraulic fluid from a pump 71 for the working members. The hydraulic fluid controlled by the boom control valve 72 and the bucket control valve 73 is supplied, respectively, to a boom hydraulic cylinder and a bucket hydraulic cylinder.
When a hydraulic signal (pilot pressure) acts on the boom down position port 72a of the boom control valve 72, the boom hydraulic cylinder is driven toward the boom down position, and the boom is actuated toward the down position. And when a hydraulic signal acts on the boom up position port 72b of the boom control valve 72, the boom hydraulic cylinder is driven toward the boom up position and the boom is actuated toward the up position. Similarly, when a hydraulic signal acts on the bucket dump position port 73a of the bucket control valve 73, the bucket hydraulic cylinder is driven toward the bucket dump position, and the bucket is actuated toward the dump position. And when a hydraulic signal acts on the bucket excavation position port 73b of the bucket control valve 73, the bucket hydraulic cylinder is driven toward the bucket excavation position, and the bucket is actuated toward the excavation position.
Accordingly, when the right operation lever 6R is operated in the forward direction, the boom is actuated toward the down position, whereas when it is operated to the rear, the boom is actuated to move up. When the right operation lever 6R is operated to the right, the bucket is actuated toward the dump position, and when it is operated to the left, the bucket is actuated toward the excavation position.
FIG. 14 is a hydraulic circuit diagram for the case where the left and right running bodies are actuated by operating the left and right operation levers 6L and 6R (cf FIG. 12(a)). The configuring elements common to FIG. 13 are not further described here.
The left operation lever 6L is connected to the left running body hydraulic pump 33 and to the boom control valve 72 by lines 91 and 92, respectively. The line 91 is a line wherein hydraulic signals are generated in response to operations of the left operation lever 6L in the forward and backward directions. The line 92 is a line wherein hydraulic signals are generated in response to operations of the left operation lever 6L to the left and right.
The right operation lever 6R is connected to the right running body hydraulic pump 34 and to the bucket control valve 73 by lines 93 and 94, respectively. The line 93 is a line wherein hydraulic signals are generated in response to operations of the right operation lever 6R in the forward and backward directions. The line 94 is a line wherein hydraulic signals are generated in response to operations of the right operation lever 6R to the left and right.
Accordingly, when the left operation lever 6L is operated in the forward direction, the vehicle xe2x80x9cmoves ahead to the left,xe2x80x9d and when it is operated to the rear, the vehicle xe2x80x9cmoves back to the left.xe2x80x9d When the left operation lever 6L is operated to the right, the boom is actuated to move down, and when operated to the left, the boom is actuated to move up. When the right operation lever 6R is operated in the forward direction, the vehicle xe2x80x9cmoves ahead to the right,xe2x80x9d and when operated to the rear, the vehicle xe2x80x9cmoves back to the right.xe2x80x9d When the right operation lever 6R is operated to the right, the bucket is actuated toward the dump position, and when operated to the left, the bucket is actuated toward the excavation position.
Thus, as described in the foregoing, for a vehicle such as a skid steer loader, there is an operation pattern (called the first operation pattern) for, actuating the left and right running bodies by operating only one operation lever (the left operation lever 6L), and an operation pattern (called the second operation pattern) for actuating the left and right running bodies by operating both the left and the right operation levers 6L and 6R.
As seen in Japanese Utility Model Application Publication No. 38935/1994, described in the foregoing, although there is prior art for switching the operation pattern for actuating working members, there is no prior art relating to switching between the first operation pattern and the second operation pattern for actuating the running bodies.
A first object of the present invention is to make it possible to switch between the first operation pattern and the second operation pattern, enhance the operability of such vehicles as skid steer loaders, and reduce the burden on the operator.
A second object of the present invention is to make it easy to switch between an operation pattern wherewith two actuators are driven by only one of two operation apparatuses and an operation pattern wherewith the two actuators are driven by operating both of the operation apparatuses.
It is noted that inventions have already been publicly disclosed that relate to an operation lever device wherewith operation signals are generated by operating a single operation lever so as to tilt, and the driving of two hydraulic actuators is controlled based on those operation signals.
In Japanese Patent Application Laid-Open No. 89515/1997, for example, an electrical operation lever apparatus is disclosed wherewith, by tilting operations with a single operation lever, the displacements in each of four pistons are output as electrical signals. The driving of two hydraulic actuators is controlled on the basis of the electrical signals output from that electrical operation lever apparatus.
In World Patent Publication No. WO 96/15374 is disclosed a hydraulic operation lever apparatus that outputs hydraulic signals.
In FIG. 26(a) is diagrammed a section of the essential parts of a hydraulic operation lever apparatus. By operating a single operation lever so that it tilts, the displacements in each of four pistons are output as hydraulic signals. In FIG. 26(b) is given a diagonal view of the configuration of a universal coupling 150 indicated in FIG. 26(a). Two hydraulic motors mounted in a hydraulic drive vehicle are drive-controlled by the operation lever apparatus diagrammed in FIG. 26. In FIGS. 27(a) and 27(b) are diagrammed the movements of the operation lever indicated in FIG. 26. A description is now given with reference to these drawings.
The operation lever apparatus 105 diagrammed in FIG. 26(a) consists mainly of a main apparatus body 107 and an operation lever 106 that is deployed so that it can be tilted in relation to the main apparatus body 107.
The operation lever 106 is attached to the main apparatus body 107 through the universal coupling 150 and a disk plate 108.
As diagrammed in FIGS. 27(a) and 27(b), four pistons 101, 102, 103, and 104 are deployed so that the piston tips (upper ends) protrude from an attachment plate 111. These pistons 101, 102, 103, and 104 are arranged so that, as viewed from the upper surface of the attachment plate 111, they are positioned at the four corners of a square. When the operation lever 106 is tilted in the F direction and the piston 104 is depressed, the vehicle moves forward. When the operation lever 106 is tilted in the B direction and the piston 102 is depressed, the vehicle moves back. When the operation lever 106 is tilted in the R direction and the piston 101 is depressed, the vehicle executes a right spin turn. And when the operation lever 106 is tilted in the L direction and the piston 103 is depressed, the vehicle executes a left spin turn. By spin turn here is meant a spin turn. This means that the vehicle turns without the center of the vehicle moving. More concretely described, this refers to a turning movement effected when the wheels or crawlers provided in the vehicle turn at the same speed in opposite directions.
FIG. 26(a) is a section looking at FIG. 27(a) from the left.
A fork-shaped bracket 112 is attached to the main apparatus body 107. As diagrammed in FIG. 26(b), the universal coupling 150 comprises the fork-shaped bracket 112, a tilting member 113, a support shaft 109, and a support shaft 110. The tilting member 113 is deployed in the fork-shaped bracket 112 by the support shaft 110. The operation lever 106 is deployed in this tilting member 113 by the support shaft 109. In other words, the operation lever 106 is attached to the main apparatus body 107 through the universal coupling 150.
The support shaft 109 in the universal coupling 150 is deployed so that the axis thereof is at right angles to the support shaft 110.
The support shaft 109 is parallel to the upper surface of the attachment plate 111 and at right angles to the surface of the drawing. This support shaft 109 supports the operation lever 106 so that it can be turned about the axis of the support shaft 109. That is, the operation lever 106 can be tilted to the left and right, in FIG. 26(a), by turning it about the axis of the support shaft 109.
The support shaft 110 is parallel to the upper surface of the attachment plate 111 and perpendicular to the support shaft 109 described above. The support shaft 110 supports the tilting member 113 in relation to the fork-shaped bracket 112 so that it can turn about the axis of the support 110. That is, the operation lever 106 can be tilted in directions that are at right angles to the drawing surface in FIG. 26(a) by turning it together with the tilting member 113 about the axis of the support shaft 110.
With the universal coupling 150 configured in this manner, the operation lever 106 can tilt in two directions that are mutually perpendicular to the main apparatus body 107.
The disk plate 108 is attached to the operation lever 106 so that the tips (upper ends) of the pistons 101, 102, 103, and 104 strike the lower surface thereof.
Accordingly, the pistons 104 and 102 are displaced in response to the direction in and amount by which the operation lever 106 is tilted. Although not shown in FIG. 26(a), the same is true of the pistons 101 and 103.
In the main apparatus body 107 are provided hydraulic signal generation means for generating hydraulic signals of sizes corresponding to the displacements in each of the four pistons 104, 102, 101, and 103. The pistons 104, 102, 101, and 103 correspond to pilot lines 114, 115, 116, and 117, respectively (cf. FIG. 27(b)).
The operation of the operation lever apparatus 105 described in the foregoing is now described.
FIG. 26(a) shows the operation lever 106 in the neutral position. It is now assumed that from this position the operation lever 106 is tilted about the axis of the support shaft 109 (to the left in the drawing). Thereupon, the piston 104 on the left side of the figure is depressed in the direction of the arrow A by the disk plate 108.
When the piston 104 is depressed, a pilot pressure Pp of a size that corresponds to the amount of tilt in the operation lever 106 is output from the pilot line 114. Similarly, the hydraulic signals indicating a pilot pressure Pp are output from the pilot lines 115, 116, and 117 when there have been displacements in the pistons 102, 101, and 103 responsive to the tilting of the operation lever 106.
In FIG. 24 and FIG. 25 are diagrammed two types of main operation patterns with respect to the relationship between the direction of tilt in the operation lever 106 and the direction of vehicle running.
FIG. 24 diagrams what is mainly an operation pattern for vehicles like skid steer loaders. The arrows in this figure indicate the directions of vehicle running corresponding to the directions of tilt in the operation lever 106.
Now let it be assumed that the operation lever 106 has been tilted in the forward (straight ahead) direction F from the neutral position, as diagrammed in FIG. 24.
At this time, only the piston 104 is displaced in the operation lever apparatus 105. Accordingly, a hydraulic signal Pp is output from the pilot line 114. In response to this hydraulic signal Pp, a hydraulic actuator (not shown) is actuated and the vehicle advances (moves straight ahead).
As diagrammed in FIG. 24, when the operation lever 106 is tilted in the back direction B, the vehicle moves backward (in a straight line). When the operation lever 106 is tilted in the right spin turn direction R, the vehicle executes a right spin turn. When the operation lever 106 is tilted in the left spin turn direction, the vehicle executes a left spin turn. When the operation lever 106 is tilted in a direction midway between the direction F and the direction R, the vehicle moves ahead while turning to the right. When the operation lever 106 is tilted in a direction midway between the direction R and the direction B, the vehicle moves back while turning to the right. When the operation lever 106 is tilted in a direction midway between the direction B and the direction L, the vehicle moves back while turning to the left. And when the operation lever 106 is tilted in a direction midway between the direction L and the direction F, the vehicle moves ahead while turning to the left.
FIG. 25 is an operation pattern mainly for vehicles such as bulldozers.
As diagrammed in FIG. 25, when the operation lever 106 is tilted in the forward direction F, the vehicle moves forward (straight ahead). When the operation lever 106 is tilted in the back direction B, the vehicle moves back (straight back). When the operation lever 106 is tilted in the right direction R, the vehicle comes to a stop. When the operation lever 106 is tilted in the left direction L the vehicle comes to a stop. When the operation lever 106 is tilted in a direction midway between the direction F and the direction R, the vehicle moves ahead while turning to the right. When the operation lever 106 is tilted in a direction midway between the direction R and the direction B, the vehicle moves back while turning to the left. When the operation lever 106 is tilted in a direction midway between the direction B and the direction L, the vehicle moves back while turning to the right. And when the operation lever 106 is tilted in a direction midway between the direction L and the direction F, the vehicle moves ahead while turning to the left.
With the conventional operation lever 106 diagrammed in FIG. 26(a), when that operation lever 106 has been operated to a prescribed operation position and released by the operator, the pistons press against the disk plate 108 due to the spring forces of return springs 143 and 144, and the operation lever 106; automatically returns to the neutral position.
The need arises here to make the vehicle continue to running as it is, even when the operation lever 106 is released. In other words, an operator performs various other operations and work besides operating the operation lever. Nevertheless, it is still necessary to hold the operation lever 106 steady even when performing other work. The operator is thus subjected to a great burden because he or she is performing a plurality of operations simultaneously. In other words, there is a need to reduce the burden falling on the operator while he or she holds the operation lever 106 in a constant operation position.
One possible way to continue making the vehicle move with the operation lever released is to maintain the tilted position of the operation lever 106.
In FIG. 28 is diagrammed an operation lever apparatus 105xe2x80x2 that can automatically hold the operation position of the operation lever 106 constant.
The operation lever apparatus 105xe2x80x2 diagrammed in FIG. 28 differs from the operation lever apparatus 105 diagrammed in FIG. 26. The operation lever apparatus 105xe2x80x2 can only be operated in one of two directions, that is, either in the forward and backward direction or in the left and right direction. For example, it might be able to move only in the forward and backward direction.
In FIG. 28, the operation lever 106 is supported by a support shaft 191 so that it is free to tilt only in a direction parallel to the plane of the drawing.
In the base member 106a of the operation lever 106 is formed a sliding surface 106b having a prescribed curvature. This operation lever apparatus 105xe2x80x2 is provided with a brake member 190 having a sliding surface of a shape corresponding to the shape of the sliding surface 106b in the base member 106a of the operation lever, described above. When the brake member 190 is pressed by a rod 192, the sliding surface of the brake member 190 and the sliding surface 106b of the operation lever base member 106a come into contact. The other configuring elements therein are configured as diagrammed in FIG. 26(a) and so are not further described here.
FIG. 28 shows the operation lever 106 in the neutral position. Let it be assumed now that the operation lever 106 is tilted away from this position in the forward direction F (on the left side in the drawing) about the axis of the support shaft 191. Thereupon, the piston 104 (on the left side in the drawing) will be depressed in the direction of the arrow A by the operation lever base member 106a. 
When the piston 104 is depressed, a pilot pressure Pp having a size corresponding to the amount of tilt of the operation lever 106 is output from the pilot line 114. When that happens, a hydraulic actuator (not shown) is actuated and the vehicle moves ahead. Similarly, when the piston 102 on the opposite side has been displaced in response to the tilt of the operation lever 106, a hydraulic signal indicating a pilot pressure Pp is output from the pilot lines 115 and the vehicle moves back.
If here the operator releases the operation lever 106 which has been operated to a prescribed operation position, with the operation lever base member 106a having been turned to a prescribed turning position, the force of friction caused by the sliding resistance between the operation lever sliding surface 106b and the brake member 190 will act opposite to the restoring turning force of the return springs 143 and 144, and the operation lever base member 106a will stop in that prescribed turning position. Hence the operation lever 106 will be held in that condition wherein it has been operated to the prescribed operation position.
The same demand to reduce the burden on an operator holding an operation position arises for the operation lever apparatus 105 that is operated with two directional components, that is, in the forward and backward direction and in the left and right direction, as diagrammed in FIG. 26(a), as for the operation lever apparatus 105xe2x80x2 operated with only one directional component as diagrammed in FIG. 28.
On the other hand, the demand also arises for releasing the holding function that holds the operation lever at the position to which it has been operated, depending on the work situation.
When the configuration has been made so that the operation lever is held in the position to which it has been operated, the following problem arises.
That is, let it be assumed that the engine stops with the operation lever still held in a tilted position. If the engine is restarted in that condition, the vehicle will suddenly take off in a direction of advance corresponding to the direction wherein the operation lever is tilted.
A third object of the present invention is to be able to hold an operation position and also be able to release a holding condition, whether with the operation lever apparatus 105xe2x80x2 that is capable of being operated only with one directional component, or with the operation apparatus 105 that is capable of being operated with two directional components, that is, both in the forward and backward direction and in the left and right direction.
A first aspect of the present invention, for the purpose of achieving the first object stated earlier, is an apparatus for altering combinations of operation apparatuses and actuators which comprises:
two (left and right) operation apparatuses (5L, 5R) for outputting operation direction signals in operation directions; and
left and right running actuators (33, 34) provided respectively for each of left and right running bodies of a vehicle, that, by driving in drive directions corresponding to the operation direction signals, drive the left and right running bodies in corresponding directions;
and which alters combinations of operation direction signals of the two operation apparatuses (5L, 5R) and drive directions of the left and right running actuators (33, 34);
wherein the apparatus for altering combinations of operation apparatuses (5L, 5R) and actuators (33, 34) is further provided with switching means (40) for switching between a first combination that causes direction signals output from one operation apparatus (5L) of the two (left and right) operation apparatuses (5L, 5R) to correspond with driving directions of the left and right running actuators, (33, 34) and a second combination that causes operation direction signals output from the left operation apparatus (5L) to correspond with drive directions of the left running actuator (33), and operation direction signals output from the right operation apparatus (5R) to correspond with drive directions of the right running actuator (34).
The first aspect of the invention is now described with reference to FIGS. 1, 2, and 5.
FIG. 5 is a diagram that diagrams the configuration of switching means 40 indicated in FIG. 1 and FIG. 2.
Based on the first aspect of the invention, when a change to the first combination is designated by a pattern switching lever 46, as diagrammed in FIG. 5, the first combination (first operation pattern S1) is switched to by the switching means 40. Thereby, as diagrammed in FIG. 1, correspondences are effected between the operation direction signals output from one operation apparatus 5L of the two (left and right) operation apparatuses 5L and 5R and the drive directions of the left and right running actuators 33 and 34. As a consequence, it becomes possible to actuate the left and right running bodies by operating only one of the operation levers (i.e. the left operation lever 6L).
When a change to the second combination is designated by the pattern switching lever 46, as diagrammed in FIG. 5, the second combination (second operation pattern S2) is switched to by the switching means 40. Thereby, as diagrammed in FIG. 2, correspondences are effected between the operation direction signals output from the operation apparatus 5L on the left side and the drive directions of the running actuator 33 on the left side, and correspondences are effected between the operation direction signals output from the operation apparatus 5R on the right side and the drive directions of the running actuator 34 on the right side. As a consequence, it becomes possible to actuate the left and right running bodies by operating both the left and the right operation levers 6L and 6R.
Based on the first aspect of the invention described above, the first operation pattern S1 and second operation pattern S2 can be switched between when actuating the running bodies, operability is enhanced in vehicles such as skid steer loaders, and the burden on the operator is reduced.
A second aspect of the invention is the apparatus according to the first aspect of the invention, wherein the operation direction signals are hydraulic signals; a bridge circuit (45) in which four shuttle valves (41, 42, 43, 44) are connected in a ring is provided; and the switching means (40) switches between the first combination that passes the operation direction hydraulic signals output from the one operation apparatus (5L) of the two (left and right) operation apparatuses (5L, 5R) through the four shuttle valves (41, 42, 43, 44) in the bridge circuit (45), and causes same to act on ports (32F, 31F, 32R, and 31R) corresponding to the drive directions of the left and right running actuators (33, 34), and the second combination that causes the operation direction signals output from the left operation apparatus (5L) to act directly on ports (31F, 31R) corresponding to the drive directions of the left running actuator (33) and causes the operation direction hydraulic signals output from the right operation apparatus (5R) to act directly on ports (32F, 32R) corresponding to the drive directions of the right running actuator (34).
The second aspect of the invention is now described with reference to FIGS. 1, 2, and 5.
Based on the second aspect of the invention, as diagrammed in FIG. 5, when a change to the first combination (first operation pattern S1) is designated by the pattern switching lever 46, as diagrammed in FIG. 1, the operation direction signals output from the one operation apparatus 5L of the two (left and right) operation apparatuses 5L and 5R pass through the four shuttle valves 41, 42, 43, and 44 in the bridge circuit 45 and act on the ports 32F, 31F, 32R, and 31R corresponding to the drive directions of the left and right running actuators 33 and 34. Thereby the first combination (first operation pattern S1) is switched to.
When, on the other hand, the second combination (second operation pattern S2) is changed to by the pattern switching lever 46, as diagrammed in FIG. 5, the operation direction signals output from the left operation apparatus 5L, as diagrammed in FIG. 2, act directly on the ports 31F and 31R corresponding to the drive directions of the left running actuator 33, without passing through the four shuttle valves 41, 42, 43, and 44 in the bridge circuit 45. The operation direction signals output from the right operation apparatus 5R act directly on the ports 32F and 32R corresponding to the drive directions of the right running actuator, without passing through the four shuttle valves 41, 42, 43, and 44 in the bridge circuit 45. Thereby the second combination (second operation pattern) is switched to.
Based on the second aspect of the invention, the same benefits are realized as with the first invention. In addition, as based on the second invention, in a hydraulic circuit wherewith actuators are actuated by pilot hydraulic signals output from an operation apparatus, a first operation pattern S1 and second operation pattern S2 can easily be switched between merely by switching the pilot hydraulic signal paths.
A third aspect of the invention is the apparatus according to either the first or second aspect of the invention, further comprising two actuators for work machines; wherein: the switching means (40) switch between the first combination that causes operation direction signals output from one operation apparatus (5L) of the two (left and right) operation apparatuses (5L, 5R) to correspond with drive directions of the left and right running actuators (33, 34) and causes operation direction signals output from other one of the operation apparatuses (5R) to correspond with drive directions of the two actuators for work machines, and the second combination that causes operation direction signals output from the left operation apparatus (5L) to correspond with drive directions of the left running actuator (33) and with drive directions of one of the actuators for working machines, and causes operation direction signals output from the right operation apparatus (5R) to correspond with drive directions of the right running actuator (34) and with drive directions of other one of the actuators for working machines.
The third aspect of the invention is now described with reference to FIGS. 1, 2, and 5.
Based on the third aspect of the invention, as diagrammed in FIG. 5, when a change to the first combination (first operation pattern S1) is designated by the pattern switching lever 46, as diagrammed in FIG. 1, correspondences are effected between the operation direction signals output from the one operation apparatus 5L of the two (left and right) operation apparatuses 5L and 5R and the drive directions of the left and right running actuators 33 and 34, and correspondences are effected between the operation direction signals output from the other operation apparatus 5R and the drive directions of the two actuators for work machines. As a consequence, the left and right running bodies can be actuated by operating only the one operation lever (left operation lever 6L), and the two working members (boom and bucket) can be actuated by operating only the other operation lever (right operation lever 6R).
As diagrammed in FIG. 5, furthermore, when the second combination (second operation pattern S2) is changed to by the pattern switching lever 46, as diagrammed in FIG. 2, correspondences are effected between the operation direction signals output from the left operation apparatus 5L, on the one hand, and the drive directions of the running actuator 33 on the left side and the drive directions of one of the actuators for working machines, on the other, while correspondences are also effected between the operation direction signals output from the right operation apparatus 5R, on the one hand, and the drive directions of the running actuator 34 on the right side and the drive directions of the other actuator for work machine, on the other. As a consequence, it becomes possible to actuate the left and right running bodies by operating both the left and the right operation levers 6L and 6R, to actuate one of the working members (the boom) by operating the left operation lever 6L, and to actuate the other working member (the bucket) by operating the right operation lever 6R.
Based on the third aspect of the invention, the same benefits are obtained as with the first and second inventions. Based on the third invention, furthermore, a first operation pattern S1 and second operation pattern S2 can easily be changed between, even when using working members in addition to running bodies.
A fourth aspect of the invention, for the purpose of achieving the second object stated earlier, is an apparatus for altering combinations of operation apparatuses and actuators which comprises:
two operation apparatuses (5L, 5R) for outputting operation direction signals in operation directions as hydraulic signals; and
two actuators (33, 34) that drive in drive directions corresponding to the operation direction signals;
and which alters combinations of operation direction signals of the two operation apparatuses (5L, 5R) and drive directions of the two actuators (33, 34);
wherein the apparatus for altering combinations of operation apparatuses and actuators is further provided with switching means (40) for switching between a first combination that passes operation direction hydraulic signals output from one (51) of the two operation apparatuses (5L, 5R) through a bridge circuit (45) in which four shuttle valves (41, 42, 43, 44) are connected in a ring, and causes those signals to act on ports (32F, 31F, 32R, 31R) corresponding to the drive directions of the two actuators (33, 34), and a second combination that causes operation direction hydraulic signals output from one (5L) of the operation apparatuses to act directly on ports (31F, 31R) corresponding to drive directions of one of the actuators, and causes operation direction hydraulic signals output from other one (5R) of the operation apparatuses to act directly on ports (32F, 32R) corresponding to drive directions of other one (34) of the actuators.
The fourth aspect of the invention is now described with reference to FIGS. 1, 2, and 5.
Based on the fourth aspect of the invention, as diagrammed in FIG. 5, when a change to the first combination is designated by the pattern switching lever 46, the first combination (first operation pattern S1) is switched to by the switching means 40. Thereby, as diagrammed in FIG. 1, the operation direction signals output from one operation apparatus 5L of the two operation apparatuses 5L and 5R pass through the four shuttle valves 41, 42, 43, and 44 in the bridge circuit 45, and act on the ports 32F, 31F, 32R, and 31R corresponding to the drive directions of the two actuators 33 and 34. Thereby, the first combination (first operation pattern S1) is switched to. As a consequence, it becomes possible to drive two actuators by operating only one operation apparatus (the left operation lever 6L).
When the second combination is changed to by the pattern switching lever 46, as diagrammed in FIG. 5, the second combination (second operation pattern S2) is switched to by the switching means 40. Thereby, as diagrammed in FIG. 2, the operation direction signals output from one operation apparatus 5L act directly on the ports 31F and 31R corresponding to the drive directions of the one actuator 33, without passing through the four shuttle valves 41, 42, 43, and 44 in the bridge circuit 45. The operation direction signals output from the other operation apparatus 5R act directly on the ports 32F and 32R corresponding to the drive directions of the other actuator 34, without passing through the four shuttle valves 41, 42, 43, and 44 in the bridge circuit 45. Thereby the second combination (second operation pattern S2) is switched to. As a consequence, it becomes possible to drive two actuators by operating the two operation apparatuses (the left and right operation levers 6L and 6R).
As based on the fourth aspect of the invention, described in the foregoing, switching can easily be done between a first operation pattern for driving two actuators with only one operation apparatus of two operation apparatuses, and a second operation pattern for driving the two actuators by operating both of the two operation apparatuses.
A fifth aspect of the invention is the apparatus according to the fourth aspect of the invention, wherein: the switching means (40) comprises:
input ports (I1, I2, I3, I4) for inputting operation direction hydraulic signals output from the one of the operation apparatuses (5L);
output ports (E1, E2, E3, E4) that are connected to ports (32F, 31F, 32R, 31R) corresponding to the drive directions of the two actuators (33, 34); and
a piston (48) having a first position in which the input port (I1) is caused to communicate with the output ports (E1, E2) through the shuttle valves (41, 42) in the bridge circuit (45), and a second position in which the input port (I1) is caused to communicate directly with the output ports (E2).
The fifth aspect of the invention is now described with reference to FIGS. 1, 2, 5, and 6.
Based on the fifth aspect of the invention, as diagrammed in FIG. 6, in response to the change to the first combination (first operation pattern S1) being designated by the pattern switching lever 46, the relative position of the piston 48 with respect to a body 47 is changed to the first position. Thereby, as diagrammed in FIG. 5, the input port I1 is connected to the output ports E1 and E2 through the shuttle valves 41 and 42 in the bridge circuit 45. The same is true of the other input ports 12 to I4. Thus the first combination (first operation pattern S1) is switched to.
As diagrammed in FIG. 6, moreover, in response to the change to the second combination (second operation pattern S2) by the pattern switching lever 46, the relative position of the piston 48 with respect to the body 47 is changed to the second position. Thereby, the input port I1 is connected directly to the output port E2 without passing through the four shuttle valves 41, 42, 43, and 44 in the bridge circuit 45. The same is true of the other input ports 12, 13, and 14. Thus the second combination (second operation pattern S2) is switched to.
Based on the fifth aspect of the invention, the same benefits are gained as with the fourth aspect of the invention. As based on the fifth aspect of the invention, furthermore, switching can be performed with the simple operation of changing the relative position of the piston 48 with respect to the body 47.
A sixth aspect of the invention is the apparatus according to the fifth aspect of the invention, wherein the piston 48 is cylindrical in shape, and the rotational position thereof in relation to the body 47 changes in response to a rotating operation.
The sixth aspect of the invention is now described with reference to FIG. 6.
Based on the sixth aspect of the invention, the rotational position of the cylindrical piston 48 changes in relation to the body 47 in response to rotational operations of the pattern switching lever 46. Thus the switching means 40 are changed between a first position and a second position, and switching is effected between the first combination (first operation pattern S1) and the second combination (second operation pattern S2).
Based on the sixth aspect of the invention, the same benefits are gained as with the fourth and fifth aspect of the inventions. Based on the sixth aspect of the invention, furthermore, switching can be effected merely by performing the simpler operation of rotating the piston 48. The structure of the switching means 40 can also be simplified.
A seventh aspect of the invention is the apparatus according to either the fifth or sixth aspect of the invention, wherein the input ports (I1, I2, I3, and I4) and the output ports (E1, E2, E3, and E4) are deployed on one (47) of the body (47) and the piston (48), and the other (the piston 48) is actuated so that it assumes either the first position or the second position.
The seventh aspect of the invention is now described with reference to FIG. 6.
Based on the seventh aspect of the invention, the input ports I1, I2, I3, and I4 and the output ports E1, E2, E3, and E4 are deployed either on the side of the body 47 or on the side of the piston 48 (on the side of the body 47, for example). The other side (the piston 48) is then actuated (rotationally actuated) so that it assumes either the first position or the second position. Therefore, the problem of the lines (hydraulic lines 11, 12, 13, and 14, etc.) that are connected to the input ports I1, I2, I3, and I4 and the output ports E1, E2, E3, and E4 becoming twisted does not occur even if the piston 48 is actuated. Based on the seventh aspect of the invention, the same benefits are realized as with the fourth, fifth, and sixth aspect of the inventions.
An eighth aspect of the invention, for the purpose of realizing the third object, is an operation lever apparatus comprising:
an operation lever (106) capable of being operated so as to tilt;
drive signal generation means (120, 119, 121, 118) for generating drive signals according to the direction and amount of tilt in the operation lever (106) and outputting the same to actuators;
holding means (122, 174) for holding the operation lever (106) in a certain tilted position when the operation lever (106) has been operated so to tilt; and
hold release means (122, 174) for releasing hold conditions effected by the hold means.
The eighth aspect of the invention is now described with reference to FIG. 32 which is a specific example thereof.
Based on the eighth aspect of the invention, when the operation lever 106 is operated so as to tilt, that operation lever 106 is held in a tilted operation position for one directional component, either the component for the forward and backward directions F and B, or the component for the left and right directions L and R. In concrete terms, hydraulic fluid discharged from an operation lever pump 122 acts on a piston 174. As a consequence, a pressing force is generated at the piston 174 and the piston 174 is pushed against a support shaft 152 by a sliding member 148c. As a result, the operation lever 106 is held in the tilted position.
As diagrammed in FIG. 24 and FIG. 25, when the operation lever 106 has been operated in a direction midway between the forward direction F and the right direction R, causing the vehicle to effect a xe2x80x9cforward turn to the right,xe2x80x9d and the operation lever 106 is then released, that operation lever 106 will be held in the tilted position in the forward direction F component. As a consequence, the vehicle will continue moving in the xe2x80x9cforwardxe2x80x9d direction while maintaining the current speed of running.
Then, when a holding force release lever 176 is operated to the switch position 177b, hydraulic fluid will cease being discharged from the operation lever pump 122 that has the engine for its drive source. As a consequence, the hydraulic fluid discharged from the operation lever pump 122 will cease acting on the piston 174. As a consequence of that, the pressing force will cease being generated at the piston 174, and the condition wherein the piston 174 is pushed against the support shaft 152 via the sliding member 148c is released. As a result, the holding force on the operation lever 106 is released, and the operation lever 106 is returned to the neutral position from the tilted position.
Thus, as based on this eighth aspect of the invention, the operation lever can be held in a tilted position, and the condition wherein the operation lever is held in a tilted position can be released according to the job situation.
A ninth aspect of the invention is the apparatus according to the eighth aspect of the invention, wherein the hold release means (122, 174) releases the holding force acting on the operation lever (106) in response to the drive source (132) for the actuator being stopped driving.
The ninth aspect of the invention is now described with reference to FIG. 32 which shows a specific example thereof.
When the drive of a drive source such as an engine stops, hydraulic fluid will cease being discharged from the operation lever pump 122 that is driven by that engine or other drive source. When this happens, hydraulic fluid discharged from the operation lever pump 122 no longer acts on the piston 174. As a consequence, the pressing force will no longer be generated at the piston 174, and the condition wherein the piston 174 is pressed against the support shaft 152 by the sliding member 148c will be released. As a result, the holding force on the operation lever 106 will be released, and the operation lever 106 will be returned to the neutral position from the tilted position.
Based on the ninth aspect of the invention, the operation lever holding condition can be released without fail by the stopping of the engine or other drive source, wherefore safety is dramatically enhanced. That is, even if the engine is stopped with the operation lever held in a tilted position, the operation lever will be automatically restored to the neutral position when the engine is restarted. As a consequence, the vehicle will not suddenly begin moving as a result of restarting the engine. In other words, it is therewith possible to avoid situations where the vehicle suddenly begins moving in a direction of advance according to the direction the operation lever was tilted in when the engine was stopped the previous time.
A tenth aspect of the invention is the apparatus according to the eighth aspect of the invention, wherein: the holding means (122 and 174) and the hold release means (122 and 177) comprise:
a hydraulic pump (122) driven by the actuator drive source (132); and
a pushing member (174) that is pushed against the operation lever (106) by a pushing force responsive to the pressure of the hydraulic fluid discharged from the hydraulic pump (122);
and wherein the pushing member (174) is pushed against the operation lever (106) with a pushing force responsive to the pressure of the hydraulic fluid discharged from the hydraulic pump (122), and the operation lever (106) is held in a tilted position, when the drive source (132) is driving; and, when the drive source (132) has stopped driving, the condition where the pushing member (174) is being pushed against the operation lever (106) is released, and the condition where the operation lever (106) is held is released.
The tenth aspect of the invention is now described with reference to FIG. 31, which is a specific example.
Based on the tenth aspect of the invention, when the engine or other drive source is driving, hydraulic fluid is discharged from the operation lever pump 122. As a consequence, the hydraulic fluid discharged from the operation lever pump 122 acts on the piston 174. When the operation lever 106 is operated so that it tilts, and the support shaft 152 is turned, the piston 174 is pressed against the support shaft 152 by the sliding member 148 with a pushing force responsive to the pressure of the hydraulic fluid. Therefore the support shaft 152 stops in the turned position and the operation lever 106 is held in a tilted position.
As diagrammed in FIG. 24 and FIG. 25, when the operation lever 106 is operated in a direction midway between the forward direction F and the right direction R, the vehicle is made to effect a xe2x80x9cforward turn to the right,xe2x80x9d and the operation lever 106 is then released, the operation lever 106 will be held in a tilted position in the forward direction F component. The vehicle will therefore continue moving in the xe2x80x9cforwardxe2x80x9d direction while maintaining the current speed of running.
When, on the other hand, the engine or other drive source stops driving, the hydraulic fluid will no longer be discharged from the operation lever pump 122. As a consequence, the hydraulic fluid discharged from the operation lever pump 122 will no longer act on the piston 174. As a consequence of that, the pushing force will no longer be generated at the piston 174, and the condition wherein the piston 174 is pushed against the operation lever 106 by the sliding member 148c will be released. As a result, the holding force on the operation lever 106 will be released and the operation lever 106 will be restored to the neutral position from the tilted position.
Thus, as based on this tenth aspect of the invention, the operation lever can be held in a tilted position, and the condition wherein the operation lever is held in a tilted position can be released in response to the stopping of the drive of an engine or other drive source. The operation lever holding condition can be released without fail by the stopping of the engine or other drive source, wherefore safety is dramatically enhanced. That is, even if the engine is stopped with the operation lever held in a tilted position, the operation lever will be automatically restored to the neutral position when the engine is restarted. As a consequence, the vehicle will not suddenly begin moving as a result of restarting the engine. In other words it is therewith possible to avoid situations where the vehicle suddenly begins moving in a direction of advance according to the direction the operation lever was tilted in when the engine was stopped the previous time.
An eleventh aspect of the invention is the apparatus according to the eighth aspect of the invention, further comprising holding force adjustment means (189) for adjusting the magnitude of the holding force acting on the operation lever (106).
The eleventh aspect of the invention is now described with reference to FIG. 35.
Based on the eleventh aspect of the invention, the same benefits are realized as with the eighth aspect of the invention.
Based on the eleventh aspect of the invention, furthermore, the size of the holding force acting on the operation lever 106 is adjusted by the holding force adjustment means 189.
Thus, as based on this eleventh aspect of the invention, the size of the holding force acting on the operation lever 106 can be adjusted according to the job situation or the operating strength of the operator.
A twelfth aspect of the invention is the apparatus according to the eighth aspect of the invention, wherein the drive signal generation means (120, 119, 121, 118) are drive signal generation means (120, 119, 121, 118) that generate drive signals for causing the vehicle to move in a direction of running that is according to the direction in which the operation lever (106) is tilted and at a speed of running that is according to the amount by which the operation lever (106) is tilted, and output those signals to running actuators (135, 137).
The twelfth aspect of the invention is described with reference to FIG. 22.
Based on the twelfth aspect of the invention, the same benefits are realized as with the eighth aspect of the invention.
Based on the twelfth aspect of the invention, when the operation lever 106 is operated, drive signals for causing the vehicle to move in a direction of running that accords with the direction the operation lever 106 is tilted in and at a speed of running that accords with the amount of that tilt in the operation lever 106 are generated and output to the running actuators 135 and 137.
Specifically, correspondences are effected with either of two types of running actuator 135 and 137 (either the actuator 135 or the actuator 137) and the drive direction thereof (either the forward direction or backward direction), on the one hand, and four pistons 101, 102, 103, and 104 in the operation lever apparatus 105, on the other.
Then, when drive signals are generated for each of the four pistons 101, 102, 103, and 104 by the drive signal generation means 120, 119, 121, and 118, the running actuator corresponding to the piston at which that drive signal is being generated is driven in a corresponding drive direction, by a drive amount that accords with that drive signal. That is, when a drive signal is generated by the piston 101, the running actuator 135 corresponding to that piston 101 where that drive signal is being generated is driven in the corresponding drive direction (forward direction) by a drive amount that accords with that drive signal. When a drive signal is generated by the piston 102, the running actuator 137 corresponding to that piston 102 where that drive signal is being generated is driven in the corresponding drive direction (backward direction) by a drive amount that accords with that drive signal. When a drive signal is generated by the piston 103, the running actuator 135 corresponding to that piston 103 where that drive signal is being generated is driven in the corresponding drive direction (backward direction) by a drive amount that accords with that drive signal. And when a drive signal is generated by the piston 104, the running actuator 137 corresponding to that piston 104 where that drive signal is being generated is driven in the corresponding drive direction (forward direction) by a drive amount that accords with that drive signal.
Then the operation lever 106 is held by that operation lever 106 in a tilted position in one of the directional components, either in the forward and backward direction component F and B, or in the left and right direction component L and R. As a result, a condition is maintained wherein the running actuator corresponding to one directional component is driven in the corresponding drive direction.
Thus, as based on the twelfth aspect of the invention, as diagrammed specifically in FIG. 24, when the operation lever 106 is operated in a direction midway between the forward direction F and the right direction R, the vehicle is made to effect a xe2x80x9cforward turn to the right,xe2x80x9d and the operation lever 106 is then released, that operation lever 106 is held in a tilted position in the forward direction F component. As a consequence, the vehicle runs in the xe2x80x9cforwardxe2x80x9d direction while maintaining the current speed of running.